GE Power Quality Meter Series Instruction Manual page 260

A.1 PQM APPLICATION NOTES
Any sample that deviates from its corresponding reference sample by the amount V
as calculated above is detectable by the PQM.
A
EXAMPLE:
Consider a PQM with a nominal VT secondary voltage of 100 V into the VT inputs. The trace memory trigger
for a Phase A undervoltage level of 90 V is enabled with the following setpoints:
S2 SYSTEM SETUP \ CURRENT/VOLTAGE CONFIGURATION \ VT NOMINAL SECONDARY VOLTAGE: 100 V
S1 PQM SETUP \ TRACE MEMORY \ VA UNDERVOLTAGE TRIG LEVEL: 90%
In the waveform below, an undervoltage fault occurs in the second cycle. The first cycle RMS voltage is 100 V;
the second cycle RMS voltage is 50 V, triggering the trace memory feature for the settings above.
A centered one cycle undervoltage fault is shown below. In this case, the first cycle RMS voltage is 79.05 V
and the second cycle RMS voltage is 79.05 V, triggering the trace memory feature for the settings above.
A half cycle undervoltage fault is shown below. In this case, the first cycle RMS voltage is 70.07 V and the sec-
ond cycle RMS voltage is 100 V, triggering the trace memory feature for the settings above.
A-10
200
150
100
50
0
–50
–100
–150
–200
200
150
100
50
0
–50
–100
–150
–200
200
150
100
50
0
–50
–100
–150
–200
PQM Power Quality Meter
APPENDIX A
for a minimum duration
k 2
GE Power Management